Snap switch



July 30, 1963 J. o. ROESER 3,099,723

SNAP SWITCH Filed Dec. 20, 1961 INVENTOR.

Joh n 0. P065 er ATT'Y.

3,099,723 Patented July 30, 1963 3,09,723 SNAP SWITCH John 0. Roeser,Park Ridge, Ill., assignor to Illinois Tool Works Inc Chicago, 111., acorporation of Delaware Filed Dec. 20, 1961, Ser. No. 160,828 8 Claims.(Cl. 2tltl67) This invention relates in general to control devices forelectrical circuits and more particularly relates to control devices ofthe snap acting variety.

It is a general object of this invention to provide a snap actingelectrical control device which has a minimum number of parts, is easyto manufacture, and is well adapted for the purposes of switchingelectrical currents.

A further object of this invention is to provide a snap acting switchwherein the switch body is made of a tough plastic material which isrelatively rigid in thick section and which is relatively flexible inthin secton, whereby the actuator and the body portion of the switch maybe molded in a one piece unit.

It is a further object of this invention to provide a snap acting switchwhich has an electrically conductive blade portion which serves the dualfunction of providing snap action to the movable contact and retainingthe actuator in operative relationship thereto.

It is a further object of this invention to provide a switch of thecharacteristics above set forth which is formed of a thermoplasticmaterial wherein the terminals and/or any electrical conductive partsmay be heat sealed into operative relationship on the switch body.

The novel features that are characteristic of the invention are setforth with particularity in the appended claims. The invention itself,however, both as toits organization and its method of operation,together with additional objects and advantages thereof, will best beunderstood by the following description of specific embodiments whenread in connection with the accompanying drawings in which:

FIG. 1 is a top plan view of one form of the invention;

FIG. 2 is a side elevational view along lines 22 of FIG. 1;

FIG. 3 is a sectional view along lines 3-3 of FIGS. 1 and 2;

FIG. 4 is a plan view of one of the components shown in FIGS. 1 and 2;

FIG. 5 is an enlarged fragmentary view of a portion of FIG. 2;

FIG. 6 is an isometric perspective view of the components in analternate form of switch construction embodying the inventive concepts;

FIG. 7 is a View, similar in many respects to FIG. 2, showing anotheralternate form of the invention; and

FIG. 8 is a sectional view along lines 8-8 in FIG. 7.

The switch 10 comprises the body means 12, 1a flexible blade means 14carrying the movable cont-act and providing the common terminal of theswitch as well as providing the snap action, a first fixed contact means16, and a second fixed contact means 18.

The body means 12 is preferably formed of a tough durable moldablethermoplastic which has insulating characteristics and which isrelatively rigid in relatively thick section and is relatively flexiblein relatively thin section. One material suitable for this purpose is apolycarbonate plastic manufactured by General Electric Co. and soldunder the trademark Lexan. The body means 12 essentially comprises abase portion 20 which is of a thickness in cross-section to provide arelatively rigid construction having a raised integral lug portion 22 atone end thereof. The top surface 24 of lug 22 is essentially flat andwaced a predetermined distance above the base portion 20. At the otherend of the body means 20 is a second integral raised or elevated lugportion 26 having an integral arm 28 which terminates in a free end 30.It will be noted that arm 28 is integral with the body 28' and in factthe whole body means 12 is adapted to be molded as a single part. Thearm 28 is relatively narrow in width and has a varying verticalcross-sectional dimension to provide a flexing hinge portion 32 adjacentto upstanding end lug 26 to impart movability to the free arm 30. Inessence, portion 32 provides the function of a hinge and due to theincrease in cross-section of arm 28 as it progresses towards its freeend 38, the arm 28 essentially acts as a lever arm and is relativelyrigid except at the hinge point 32.

By molding arm 28 in an upright position (at substantially right angleto the base portion 28) and then in assembly, deflecting the armdownwardly for assembly to the blade means 14, the arm 28 will be biasedupwardly by the internal stresses therein. It will be noted that arm 28after assembly to the blade means 14 is substantially parallel with thebody portion 20 and is substantially aligned with the longitudinal axisof body portion 20. The arm 28 has a length slightly shorter than thebody portion 20 and terminates short of raised lug 22 so that the freeend portion 30 will not interfere with lug 22 upon vertical downwardmovement thereof from the position shown in FIG. 2 and its subsequentreturn.

The free end 30 of arm 28 is formed with an actuator engageable cam lugsurface 34 on the upward side thereof as viewed in FIGS. 2 and 5, and isformed with a depending portion 36. A longitudinally extending lugportion 38 is formed at the bottom of depending lug 36 which extends inthe direction of body lug portion 22. On the opposite side of dependingportion 36, a somewhat V- shaped groove 40* formed for assembly purposeshereinafter appearing.

The electrically conductive blade means 14 may be formed of thinflexible material, for example, beryllium copper, and may have aninitially flat generally rectilinear shape. By a suitable stampingoperation, a central tongue 44 may be blanked out of the blade means ina manner to provide a pair of spaced arms 42 of the configuration asshown in FIG. 4. A blade mounting aperture 46 may be formed in the bodyof blade means '14 in a position essentially opposite the end 52 of thetongue 44. A tab 48 having an aperture therein for electrical connectionto suitable wires is provided at one end of the blade body. The movablecontact 50 is disposed on the blade means on the end opposite to tab 48.There are many Ways of mounting the blade means 14 to the switch bodymeans, one such being the molding of an integral lug 54 which willproject through aperture 36 of the blade means 14 and then beat sealingand squashing down the lug to fixedly mount the blade in position on theswitch.

After the blade means 14 is mounted to lug surface 24, the end surface52 of tongue 44 is disposed in notch 40 on the underside of the free arm28 of the body means as shown in FIGS. 2 and 5. Lug surface 38 isinserted underneath the blade means and is retained by interferencetherewith as shown. The tongue 44 is bowed and is under compression soas to exert tension on the arms 42. Movement of the free end 30 of thebody means about hinge point 32 will cause the movable contact 51 on theblade means to move With a snap action between the upper and lower fixedcontacts 18 and 16.

The fixed contact 16 may be of any suitable type, one type being shownas a metal stamping having a depending portion 56, a notch portion 58,and a horizontal portion 68. The notch portion 58 fits into a suitablerecess formed in the side of the body means base portion and may beretained in position by any number of means, one such being heat sealingby projecting portions of the body over the notched out portion 58. Thehorizontal surface 60 becomes the lower fixed contact of the switch. Theother fixed contact 18 is substantially similar except that horizontalportion 64!- is located above the depending portion 62 to provide theupper fixed contact. Fixed contact 18 may be retained in the same manneras fixed contact 16 and is disposed on the other side of the switchbody. Both of the fixed contacts 16 and 18 may have suitable holes 66 inthe respective depending portions 56 and 62 to aid in attachment ofsuitable electrical circuitry.

A modified form of the invention is shown in FIG. 6 and similar partswill be identified with similar reference numerals with the addition ofthe suffix a. Switch 10a is essentially similar in the method ofmounting the fixed contacts 16a and 18a and in overall configuraiton ofthe body means 12a. A different type of blade means Ma is employed.Blade means 14a differs in that the two arms 42a on either side of thecentral tongue are completely separate from the central tongue 44a andare shorter in length. The central tongue 44a extends sufiiciently so asto aiford the aperture 46a to be fitted over mounting lug 54a which hasan undercut surface adjacent surface 24:: so as to retain the tongue 44.in fixed relationship to the switch body. The end surfaces 68 of thearms 42a are disposed in notches 70 formed in the body means lug portion22a as shown. Due to the relative positioning of the aperture 46a andthe iength of the arms 42a, the tongue portion 44 is put into tensionand the arms 42a are predisposed into a sinusoidal wave by the raisedlugs 72 on the switch body. The free end 300: of arm 28a is formed withthin lips 74 which fit over the central tongue 54 and retain the headportion in operative engagement with tongue 44. The channel 76 so formedin the underside of the free end a traps the tension arm 34 anddepression of the head 34 causes the contact a to move between the fixedcontacts 16a and 18a.

Still another modified form of the invention is shown in FIGS. 7 and 8and similar parts shall be identified with similar reference numeralswith the addition of the sufiix b. The form of switch 10b shown in FIG.7 is basically similar to that shown in FIG. 1 except for the followingdifierences. The hinge portion 32b of switch 106 is offset closer to themidpoint of the switch so as to give a thickened portion 84- adjacent toupstanding switch body lug 26b. Thus, electrical terminals in the formsof wires 80 and 82 may be disposed in operative engagement with printedcontacts 86 and 88 which are formed on the opposed surfaces of the bodyportion 20b and 84 as shown in FIG. 8. The terminal wires 80 and 82 maybe conveniently mounted in the body by putting a short durationrelatively high amperage electrical current through the wires to meltthe plastic while forcing them towards each other. Upon cooling, theheated plastic puddles around the wires and maintains them in strongphysical engagement with the body and in electrical engagement with therespective contacts 86 and 88. The common terminal wire member 78 may bemounted similarly to terminal wires 80 and 82 if desired. One furtherdistinction of the instant embodiment is that the lug 54b is formed withan undercut so that the aperture 4 46b fits over the lug and the blademeans is retained by the force imposed by the tongue 44b. This is anexceed ingly simple assembly operation requiring a simple positioningand no post operation is required to maintain the body and the blademeans in assembled relationship.

Although specific embodiments of the invention have been shown anddescribed, it is with full awareness that many modifications thereof arepossible. The invention, therefore, is not to be restricted exceptinsofar as is necessitated by the prior art and. by the spirit of theappended claims.

What is claimed as the invention is:

1. A snap switch construction of minimum parts comprising in combinationa one piece U-shaped switch body of flexible insulating material havingfirst and second spaced apart substantially parallel portions integrallyjoined by a bight portion, fixed contact means fixedly mounted on saidfirst portion, integral hinge means formed in said second portionintermediate the free end thereof and said :bight portion, and snapaction movable contact means having a portion fixed to said firstportion of said switch body, means on said second portion of said switchbody adjacent the free end and spaced from said hinge means forstressedly mounting another portion of said contact means wherebymovement of said free end said second body portion causes snap actionmovement of said movable contact means relative to said fixed contactmeans.

2. A switch comprising switch body means integrally formed in one pieceof relatively flexible thermoplastic insulating means, said body meanshaving a thickness at one portion thereof to provide a relatively rigidportion and a lesser thickness in another portion to provide arelatively movable integral free end, said free end overlying saidrelatively rigid portion of said body means, flexible contact carryingelectrically conductive blade means having a contact mounted on a firstportion thereof, said blade means having a second portion fixed to saidrelatively rigid portion of said body means and disposed intermediatesaid free end and said relatively rigid portion of said body means, saidblade means being formed with a third portion, means on said free end ofsaid body means mounting said third portion of said blade means toimpart a snap action movement to said first portion of said blade means,and fixed contact means mounted on said body means for engagement bysaid contact on said contact carrying blade means whereby movement ofsaid firee end of said body means causes snap movement of said contacton said contact carrying blade means.

3. A switch comprising one piece switch body means formed of toughthermoplastic insulating means having a. rigid portion and at least onerelatively movable integral free end connected to said rigid portion bya thin integral hinge means portion, flexible contact carryingelectrically conductive sheet metal blade means having a contact mountedon a first portion thereof, said blade means having a second portionfixed to said rigid portion of said body means, said blade means beingformed with a third portion means adjacent said free end of said bodymeans engaging said third portion to impart a snap action movement tosaid firs-t portion of said blade means, means on said free end forengagement by an actuator, and at least a pair of fixed contact meansmounted on said body means for engagement by said contact on saidcontact carrying blade means whereby actuator engagement of said meansengageable by an actuator causes movement of said free end of said bodymeans to cause snap movement of said contact on said contact carryingblade means between said pair of fixed contact means.

4. The switch set forth in claim 3 wherein said third portion of saidblade means is a tensioned portion also fixed to said rigid portion ofsaid body means.

5. The switch set forth in claim 3 wherein said third portion of saidblade means is an integral tongue struck 5 out of said blade means andput into compression engagement with said free end.

6-. The switch set fonth in claim 3 wherein said free end of said bodymeans is the end portion of a substantially elongated arm portiondisposed in substantially parallel spaced relation to said relativelyrigid portion of said body means and in overlying relationship to atleast a portion of said blade means.

7. The switch set fonth in claim 6 wherein at least a portion of saidfiree end is trappingly disposed below said blade means to maintainoperative engagement therewith.

6 8. The switch set forth in claim 3 wherein the pair of fixed contactmeans are printed on said body means and are electrically connected toterminal wires heat sealingly attached to said body means.

Satterlee Aug. 17, 1943 Dillon May 8, 1962

1. A SNAP SWITCH CONSTRUCTION OF MINIMUM PARTS COMPRISING IN COMBINATIONA ONE PIECE U-SHAPED SWITCH BODY OF FLEXIBLE INSULATING MATERIAL HAVINGFIRST AND SECOND SPACED APART SUBSTANTIALLY PARALLEL PORTIONS INTEGRALLYJOINED BY A BIGHT PORTION, FIXED CONTACT MEANS FIXEDLY MOUNTED ON SAIDFIRST PORTION, INTEGRAL HINGE MEANS FORMED IN SAID SECOND PORTIONINTERMEDIATE THE FREE END THEREOF AND SAID BIGHT PORTION, AND SNAPACTION MOVABLE CONTACT MEANS HAVING A PORTION FIXED TO SAID FIRSTPORTION OF SAID SWITCH BODY, MEANS ON SAID SECOND PORTION OF SAID SWITCHBODY ADJACENT THE FREE END AND SPACED FROM SAID HINGE MEANS FORSTRESSEDLY MOUNTING ANOTHER PORTION OF SAID CONTACT MEANS WHEREBYMOVEMENT OF SAID FREE END OF SAID SECOND BODY PORTION CAUSES SNAP ACTIONMOVEMENT OF SAID MOVABLE CONTACT MEANS RELATIVE TO SAID FIXED CONTACTMEANS.